There are three main populations of harp seals, each of which has its own migratory route. The northwest Atlantic population, which breeds and molts in the Gulf of St. Lawrence, Labrador, and Newfoundland, travels to Hudson Bay, off the coast of Baffin Island, northwestern Greenland and northern Labrador to feed in early summer. The group that breeds in Jan Mayen spends its summers between Svalbard and Greenland. The population which breeds in the White Sea travels north to the Cara and Barents Seas for the summer. In September, all three of the groups begin to travel south again toward their breeding grounds. They will arrive in their respective breeding grounds in January or February. Some of the juvenile and non-breeding harp seals may remain in the northern feeding areas year round. ("Harp Seals", 2004; "Pagophilus groenlandicus", 2008; Kovacs, 2008; "Pagophilus groenlandicus: Harp Seal", 2009; Novak, 1999; Schliemann, 1990)

Physical Description

Harp seals boast a wide range of pelages through their development. Harp seal pups are born with a white coat of embryonic fur or lanugo, which gives them the name “whitecoats.” Some pups’ fur may be dyed yellow at birth by amniotic fluid, but it fades to white after a few days. About 21 to 22 days later, pups begin to lose their white fur in tufts, creating a “jagged coat.” The lanugo is replaced by a silver-white coat with irregular black spots, which the juvenile seal or “beater” retains for a year. After 12 to 14 months the blacks spots grow larger and the seal is called a “bedlamer.” The seal remains a bedlamer until it reaches sexual maturity. When the seal reaches sexual maturity (around 5.5 years old), the blacks spots converge into a “harp” shaped design, which is composed of two black lines that run up the dorsal side of the seal’s flanks, starting at their pelvis and curving and converging between the shoulders. Also, adult harp seals develop a black head and may have black markings where the hind flippers meet the body of the seal. Some harp seals retain their spotted pelage (“spotted harps”). Of the seals that retain their spots, some have dark gray streaks, creating a completely gray pelage (“sooty harps”). The harp-shaped design on the backs of adults, along with the black head and sliver-white fur, helps Pagophilus groenlandicus stand out from the other members of Phocidae that share its habitat. ("Harp Seals", 2004; Jefferson, et al., 1994; "Pagophilus groenlandicus: Harp Seal", 2009; Novak, 1999; Schliemann, 1990)

Adult harp seals have fairly small hind flippers and the fore flippers are pointed with short digit tips that boast large claws. Their heads are flat and wide and they tend to have a fairly long, but tapered snout. (Jefferson, et al., 1994)

Harp seals breed 10 to 12 days following the birth of their pups. Females enter estrus and breed near the end of lactation. The gestation period is divided into four months of delayed implantation and 7.5 months of active gestation. Birthing of harp seal pups occurs from late February to April. Females give birth on the ice near open water. Harp seals birth one pup at a time, they are nursed and cared for by their mother for 10 to 12 days. The mother’s milk is 48% fat and the pups gain an average of 33 kg while they nurse. Once the pup is weaned it is abandoned by its mother and remains alone on the ice as it waits for its silver-gray pelage to grow in so it can go into the water. While the pup waits, it loses up to 50% of its body fat. Pup mortality is 20 to 30%. ("Harp Seals", 2004; "Pagophilus groenlandicus", 2008; Jefferson, et al., 1994; Kovacs, 1995; Kovacs, 2008; "Pagophilus groenlandicus: Harp Seal", 2009; Novak, 1999; Schliemann, 1990)

Behavior

Harp seals may travel up 5000 km in a year. The migratory patterns of Pagophilus groenlandicus depend on where the seal population breeds and molts. Harp seals breed (February to April) on the southern edge of their range in the winter and molt (April to May) nearby in the spring. After molting, harp seals migrate to the northern end of their range for the summer. Harp seals begin their journey back to their breeding grounds in September. ("Harp Seals", 2004; Kovacs, 2008; "Pagophilus groenlandicus: Harp Seal", 2009; Novak, 1999; Schliemann, 1990)

Harp seals spend most of their time in the open waters, but come out of the water on a regular basis (called “haul out”) to spend some time on land. Seals tend to haul out at night. The two longest haul outs take place during the breeding season and when it is time to molt. If extended amounts of time are spent on the ice, harp seals make holes in the ice (60 to 90 cm in diameter) for easy access to water and to breathe when swimming under the ice. (Moulton, et al., 1999; Novak, 1999)

Communication and Perception

The main form of long and short distance communication for Pagophilus groenlandicus is underwater calling. Research suggests that harp seals actually listen to individual calls and respond with a specific response, rather than making random sounds. By actually listening to calls, seals can avoid masking other seals' calls. Harp seals may use underwater calling to attract mates and to coordinate herds. ("Pagophilus groenlandicus: Harp Seal", 2009; Serrano and Terhune, 2002)

Harp seals are carriers of the Phocine distemper virus (PDV). PDV does not have any affect on harp seals, but they may have passed the virus onto harbor seals, ignighting a huge epidemic in Europe in 1988. (Kovacs, 2008)

Conservation Status

Due to limitations on slaughter and the involvement of conservation groups, harp seals not a threatened species and their numbers have actually begun to increase over the last few years. They are listed as "least concern" on the IUCN Red List. ("Harp Seals", 2004; Kovacs, 2008)

Other Comments

There are two sub-species of Pagophilus groenlandicus, Pagophilus groenlandicus oceanicus and Pagophilus groenlandicus groenlandicus. Pagophilus groenlandicus oceanicus breeds in the White Sea and Pagophilus groenlandicus groenlandicus breeds in the western Atlantic Ocean off of North America and the coast of Jan Mayen in the Greenland Sea. Though the two subspecies do not seem to interbreed, they have no differences in morphology or protein polymorphisms. (Kovacs, 2008)

Pagophilus groenlandicus was formerly known as Phoca groenlandica. (Kovacs, 2008)

Glossary

the body of water between Europe, Asia, and North America which occurs mostly north of the Arctic circle.

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

delayed implantation

in mammals, a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months.

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

holarctic

a distribution that more or less circles the Arctic, so occurring in both the Nearctic and Palearctic biogeographic regions.

Found in northern North America and northern Europe or Asia.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

piscivore

an animal that mainly eats fish

polar

the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polygynous

having more than one female as a mate at one time

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic.
Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

Kovacs, K. 1995. Harp and hooded seals - a case study in the determinants of mating systems in pinnipeds. International Symposium on the Biology of Marine Mammals in the North East Atlantic, Developments in Marine Biology 4: 329-335.

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This material is based upon work supported by the
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Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.